Shared characteristics among those who co-ingest cocaine and alcohol prior to death by suicide: An examination of trends within the National Programme on Substance Use Mortality data

Abstract

Background

Whilst substance dependence is well-documented as a risk factor for suicide, less is understood about individuals who die by suicide following recreational polydrug use. Cocaethylene, a psychoactive metabolite produced by the co-ingestion of alcohol and cocaine, may be a cumulative risk factor for suicidality. This study examines the sociocultural, psychiatric and toxicological complexity of individuals whose deaths by suicide involved both alcohol and cocaine use.

Methods

Data were sourced from the National Programme on Substance Use Mortality (2007–2023), including coronial reports for 147 individuals where both cocaine and alcohol were present at post-mortem. Descriptive analyses examined sociodemographics, psychiatric diagnoses, prescribed medications, substance use, and method of suicide.

Results

The cohort was predominantly male (72.4%), aged 25–45, and overrepresented in the most deprived socio-economic deciles. Psychiatric morbidity was high: over half had documented mental health conditions, and 32.6% were in receipt of psychotropic medication at the time of death. Nearly one-third of medicated cases showed markers of pharmacological complexity, including treatment-resistant prescriptions and high-risk polypharmacy. Hanging was the most frequent method of suicide (72.1%), consistent with national trends in suicide.

Conclusion

Individuals who die by suicide following the co-use of alcohol and cocaine appear to represent a highly vulnerable and clinically complex group. Cocaethylene may serve as a marker for heightened psychiatric and behavioural risk. These findings underscore the need for integrated, cross-sector care models and routine suicide risk screening in substance use settings. Structural deprivation, psychiatric complexity and impulsivity are prominent factors in this population.

Keywords

cocaethylene suicide cocaine alcohol coroners’ reports

Introduction

Whilst the association between drug and alcohol dependence and suicide risk is relatively well-characterised (Chai et al., 2022; Crump et al., 2021; Miller et al., 1991; Rizk et al., 2021), comparatively less is known about the relationship between non-dependent or recreational substance use and completed suicide. Evidence suggests that recreationally used substances such as cannabis and stimulants are frequently detected in suicide deaths, especially among those with other psychosocial or mental health risk factors (Devin et al., 2023; Shamabadi et al., 2023). Notably, fatal suicides involving stimulant use often employ violent methods such as hanging (Devin et al., 2023; Espiridion and Charron, 2024). The data highlight that the relationship is complex, with recreationally used substances acting as potential risk factors in the presence of vulnerabilities such as psychiatric illness, substance dependence or social adversity (Devin et al., 2023; Soboka et al., 2024). This underscores the necessity for further research on recreational drug use and suicide risk regardless of dependence status. In particular, the acute co-ingestion of substances such as alcohol and cocaine, in the absence of a formal diagnosis of substance use disorder has received limited scrutiny in forensic and clinical research. A recent review by Morentin et al. (2023) found that alcohol and cocaine were detected in 27% of suicide deaths, with recent consumption of either substance associated with significantly elevated risk of suicide. Complementary epidemiological and clinical data suggest that both alcohol (Innamorati et al., 2008; Windle et al., 1992) and cocaine (Oliveira Gracini et al., 2024) even at recreational levels are associated with increased odds of suicidal ideation and behaviour. Specifically, alcohol use has been linked to hopelessness, depressive symptoms and more permissive attitudes towards suicide (Innamorati et al., 2008), while adolescent cocaine and other psychotropic drug use have been associated with greater susceptibility to suicidal thoughts, particularly in the context of depression, life stress and familial conflict (Oliveira Gracini et al., 2024). Together, these findings suggest that substance use may contribute indirectly to suicidal risk by amplifying underlying psychological and environmental vulnerabilities. However, the relationship between such use and completed suicide, especially in the absence of a diagnosed substance use disorder, remains underexplored.

This gap in knowledge is important, as individuals who engage in polydrug use, even recreationally, often do so within broader psychosocial contexts of vulnerability. Substance misuse and psychological distress frequently co-occur, and both are independently associated with suicide risk (Buckley and Brown, 2006; Gibbons et al., 2024; Moggi et al., 1999; Padgett et al., 2008). Additionally, individuals with dual diagnoses (mental illness coexisting with substance misuse) face disproportionately higher rates of suicide (Liu et al., 2023; Moggi et al., 1999; Szerman et al., 2012; Youssef et al., 2016). These individuals are also more likely to be prescribed psychotropic medications, which may be indicative of psychiatric severity or treatment resistance. Indeed, Morentin et al. (2023) report that 63% of suicide decedents in their sample were positive for prescribed psychotropic medications, underscoring the link between psychiatric morbidity, psychopharmacology and suicide.

One potentially under-recognised biochemical factor in this equation is the presence of cocaethylene, a psychoactive and cardiotoxic metabolite endogenously formed when alcohol and cocaine are co-ingested (Pergolizzi et al., 2022). Cocaethylene is known to have a longer half-life than cocaine and may exert stronger cardiovascular and psychoactive effects (Cami et al., 1998; Hearn et al., 1991; Shastry et al., 2023). Indeed, the direct cardiovascular risk (including myocardial injury, sudden death and cardiac arrest) is documented in the literature (van Amsterdam et al., 2024). In addition, animal studies have shown that cocaethylene can be more toxic than either cocaine or alcohol alone, potentially increasing the physiological burden during acute substance use episodes (Landry, 1992; Xu et al., 1994). Given this, it is reasonable to propose that combined ingestion may result in an elevated cumulative risk. Evidence specifically examining alcohol–cocaine co-use (e.g. cocaethylene) in relation to suicide-related constructs is limited. Studies show that alcohol alone is frequently involved in self-harm and increases suicide risk, particularly in women (Ness et al., 2015), while cocaine use is overrepresented in suicides involving direct physical self-injury methods (e.g. cutting or other violent mechanisms), relative to its prevalence in the general population (Bailey et al., 2021). More broadly, drug use disorders (including opioids and ketamine) are associated with markedly elevated risks of self-harm and suicide (Chai et al., 2022), suggesting that co-use may contribute indirectly by amplifying established substance-related risk factors.

Nonetheless, there is a lack of direct empirical evidence demonstrating that the formation of cocaethylene after cocaine and alcohol co-use is itself a causal factor in behaviours that increase the incidence of suicide (Davies et al., 2025).

Accordingly, the cumulative effect of multiple biopsychosocial factors (including psychiatric treatment complexity, social deprivation and method of suicide) requires further investigation. Previous studies have suggested that individuals with severe mental illness, economic disadvantage and prior contact with mental health services may be at greater risk, especially when means such as hanging are involved (Hawton, 2007; Huisman et al., 2010; Hunt et al., 2009). Yet, few studies have synthesised these dimensions in a population where Cocaethylene is detected at post-mortem.

In this study, using data collated by the National Programme on Substance Use Mortality (NPSUM), we explore the sociodemographic, psychiatric, pharmacological and toxicological profiles of individuals who died by suicide and were found to have consumed both cocaine and alcohol prior to death. To be clear, the focus of this study is not on alcohol and cocaine co-use as a direct cause of death by overdose, but rather on its role as a risk factor that may exacerbate disinhibition, impulsivity and mood instability, thereby increasing vulnerability to suicidal behaviour. Understanding the confluence of these factors may offer new insights for clinical practice, service design and public health interventions targeting suicide prevention in substance-using populations. Although polydrug use is a recognised risk factor for suicide, the specific profile of individuals who die following alcohol and cocaine co-use has not been examined in detail. The detection of cocaethylene at post-mortem provides a clear indicator of this pattern of co-ingestion, which is pharmacologically distinct and associated with impulsivity, disinhibition, and hazardous substance-use behaviours. Using coronial data, this study offers one of the first integrated descriptions of the sociodemographic, psychiatric and toxicological characteristics of suicide decedents with confirmed alcohol and cocaine co-use. By characterising this subgroup, we aim to determine whether they represent a distinctly high-risk profile with implications for suicide prevention.

Methods

Decedent data

The data were sourced from the National Programme on Substance Use Mortality (NPSUM) at King's College London. The database includes coroners’ reports pertaining to psychoactive drug-related deaths from England, Wales and Northern Ireland dating back to 1997. The NPSUM includes demographic information, information related to the cause and manner of death as well as past medical and mental health histories for over 57,000 cases.

In the present study, we included only cases where both cocaine and alcohol were detected at postmortem, and where the death had been given an official coroner's verdict of suicide. In England and Wales a coroner may record a conclusion of ‘suicide’ only when the evidence satisfies the civil standard of proof, that is, that on the balance of probabilities the deceased intended to take their own life. Cases where cocaethylene was mentioned specifically by a coroner were also included. Given the plasma elimination half-life of cocaethylene (approximately 2 h, longer than cocaine), its detection was interpreted as evidence of recent alcohol-cocaine co-use and exposure to combined pharmacological effects, rather than as a precise indicator of the timing of ingestion relative to death. The following time period was included in the case selection process: 2007–2023. Routine testing or reporting of cocaethylene was not conducted before 2007, and although four pre-2007 cases recorded cocaethylene, none were classified by the coroner as suicides. Using these criteria, a total of 147 cases were extracted for further study. This study received ethical approval as a secondary data analysis from the University of South Wales Faculty of Life Sciences and Education Ethics Panel.

Data preparation and analysis strategy

To examine the rates of deprivation among the sample, decedent postcodes were used to extrapolate a score on national deprivation indices. Deprivation deciles for English postcodes were derived from the English Indices of Deprivation 2019 (Ministry of Housing, Communities & Local Government, Technical Report, 2019), while for Welsh postcodes the Welsh Index of Multiple Deprivation 2019 (WIMD) was used (Welsh Government, Technical Report, 2019).

Descriptive statistics were generated using SPSS (Version 30) for sociodemographic profile, method of suicide and associated precipitating factors, and the frequency of prescription and illicit drugs from the coroner report.

Comprehensive medical and psychiatric histories were not available for all cases within the NPSUM files; however, in many instances, relevant information was collected or received and is included where available. To provide a proxy measure of mental and physical health complexity, prescription medication data were reviewed for all included cases where such information was available. A mental or physical health condition complexity score was determined using NICE and association specific (e.g. https://www.bap.org.uk/pdfs/BAP_Guidelines-Schizophrenia2.pdf) prescribing guidelines. Medications prescribed second or third line, or those prioritised for treatment-resistant presentations conferred greater complexity scores. Furthermore, those receiving a prescription for multiple mental OR physical health conditions, were considered more complex, and were therefore assigned a higher complexity score which ranged from low, medium to high risk (Table 1).

Table 1.

Mental and physical health complexity estimation algorithm.

Risk category	Risk score (example category)	Risk score (example category)	Risk score (example category)
Prescribing guideline and stage of treatment algorithm	1 (first-line medication, e.g., sertraline for depression [20])	2 (second-line medication, e.g., mirtazapine or venlafaxine for depression [20])	3 (third-line augmentation or combination, or considered a treatment-resistant medication, e.g., quetiapine or aripiprazole [21])
Receipt of multiple medications for mental health OR physical conditions		2 (e.g. patient in receipt of a first line anti-psychotic AND first line anti-depressant)	3 (e.g. patient in receipt a non-first line medication for two conditions)
Receipt of a single high-risk medication			3 (e.g. benzodiazepines for sleep or oral morphine or fentanyl patches for pain)
Total

Results

Number of suicide deaths of those who co-ingested alcohol and cocaine

A total of 147 cases were identified from the NPSUM that were reported as suicide in the coroner's conclusion and had toxicological evidence of cocaine AND alcohol detected upon post-mortem testing. Cocaethylene was explicitly documented in all post-mortem reports.

Sample socio-demographics

The sample was predominantly male (N = 116, 78.9%) with a mean age of 34.8 years (SD = 8.7%), and while 26.5% lived alone, the majority lived with others. Most were employed in non-manual occupations (N = 86, 58.5%; Table 2).

Table 2.

Sample demographic.

Age (mean/SD)	34.83 (SD = 8.7)
Age category (N / %)	(N / %)
15–24	18 / 12.2
25–34	56 / 38.1
35–44	54 / 36.7
45–54	15 / 10.2
55–64	4 / 2.7
Gender	116 / 78.9 (male)
Living arrangement (N / %)	(N / %)
Alone	39 / 26.5
With parents	20 / 13.6
With partner	21 / 14.3
With partner and children	8 / 5.4
With friends	5 / 3.4
Other	5 / 3.4
Not known	49 / 33.3
Employment (N / %)	(N / %)
Employed (manual)	28 / 19
Employed (non-manual)	86 / 58.5
Self-employed	2 / 1.4
Childcare/houseperson	1 / 0.7
Student / pupil	3 / 2.0
Not known	27 / 18.4
Cause of death	(N / %)
Hanging (asphyxia/ cerebral hypoxia)	106 / 72.1
Intoxication (mixed substances)	23 / 15.6
Intoxication (single substance)	6 / 4.1
Multiple injuries (road traffic accident, fall)	3 / 2.0
Exsanguination	2 / 1.4
Drowning	2 / 1.4
Cardiac related	2 / 1.4
Insulin overdose	1 / 0.7
Carbon monoxide toxicity	1 / 0.7
Not known	1 / 0.7
Antecedent factors	(N / %)
Substance use history	75 / 51.0
Mental health history	72 / 49.0
Previously attempted suicide	28 / 19.0
Long-term physical health condition	22 / 15.0
Relationship breakdown	21 / 14.3
Left a suicide note	20 / 13.6
Threatened suicide*	14 / 9.5
Deliberate self-harm history	13 / 8.8
Debt or financial problems	5 / 3.4
Head injury	5 / 3.4
Criminal history	3 / 2.0
Recent bereavement	2 / 1.4
Prescribed medication
Mental health medication	48 / 32.6
Physical health medication	25 / 17

Note: Antecedent factors include both circumstances that may have contributed to the act and indicators of planning or intent. * refers to the act of a decedent warning another that they intend to take their own life at some point in the future.

The mean deprivation index score was in the 4th decile, and 61% (N = 90) of the sample fell within the lower four deprivation index deciles, indicating that the majority of the sample had higher levels of deprivation (Table 3). Deprivation was defined using the UK government's standard Index of Multiple Deprivation, which ranks areas based on factors such as income, employment, education, health, crime, housing and living environment

Table 3.

Deprivation decile data.

Deprivation decile rating	(N / %)
1	27 / 18.4
2	25 / 17.0
3	17 / 11.6
4	21 / 14.3
5	14 / 9.5
6	9 / 6.1
7	10 / 6.8
8	6 / 4.1
9	5 / 3.4
10	6 / 4.1

Note: Seven cases not included due to missing data relating to address.

Method of suicide and precipitating factors

The method of suicide most frequently reported was hanging (N = 106 / 72.1%; Table 2). This was followed by mixed substance intoxication (N = 23 / 15.5%) and single substance intoxication (N = 6 / 4.1%). Suicide by multiple injuries, exsanguination, drowning, cardiac-related, insulin overdose and carbon monoxide toxicity were less common (Table 2). There was variability regarding how the cause of death for each of method of suicide was documented (Table 4).

Table 4.

Cause of death by category and coroner's summary.

Method of suicide	Terminology used in coroner's reports
Hanging	Asphyxia, suspension by ligature, hanging by ligature, pressure on neck, lethal pressure on neck, ligature strangulation, external compression of the neck, compression of neck structures by ligature, suspension, cerebral hypoxia, hanging by neck, effects of hanging, ligature suspension, Ligature occlusion of the airways and neck vasculature, constriction by ligature, death by hanging.
Mixed substance intoxication	Poisoning by cocaine and MDMA, toxic effects of zopiclone, amitriptyline, tramadol and alcohol, combined drug toxicity (cocaine, heroin, zopiclone, benzodiazepines, pregabalin and promethazine), fentanyl and amitriptyline toxicity, mixed drug toxicity, toxic effect of heroin and other drugs, morphine toxicity potentially exacerbated by mirtazapine, pregabalin and diazepam.
Single substance intoxication	Propranolol toxicity, cocaine intoxication, methadone intoxication, heroin toxicity, venlafaxine overdose, drug toxicity (olanzapine)
Multiple injuries	Multiple injuries with severe head and brain injury, chest injury sustained in a road traffic incident, multiple injuries.
Exsanguination	Exsanguination (incised wounds to neck and wrists), exsanguination form severe self-inflicted traumatic injuries in combination with acute cocaine toxicity.
Drowning	Drowning
Cardiac-related	Sudden arrhythmic cardiac death, hypoxic encephalopathy.
Insulin overdose	Hypoglycaemic shock
Carbon monoxide toxicity	Carbon monoxide poisoning

A number of precipitating factors were identified in the sample; most commonly having a history of mental health issues (N = 75, 51%), a history of substance use (N = 72, 49%) and whether the individual had previously attempted suicide (N = 28, 19%; Table 2). Factors such as debt issues, head injury, having a forensic history and experiencing a recent bereavement were less common with case numbers ranging from two to five (1.4–3.4%).

Post-mortem toxicology: prescription and illicit drugs

Each of the decedents had post-mortem toxicological testing performed to establish the presence of substances in bodily fluids. Alcohol and cocaine or cocaethylene were present in all cases as they were part of the a-priori case selection criteria. The mean cocaine concentration was 286 mg/l (SD = 2162) and 17 mg/l (SD = 5.6) in blood and urine, respectively. The mean alcohol concentration was 123 mg/dl (SD = 72.2) and 167 mg/dl (SD = 94.2) in blood and urine, respectively. 69.3% (N = 102) of the sample was positive for having cocaine in their blood, and 6.8% (N = 10) of the sample were positive for having cocaine in their urine. Alcohol was found in the blood of 76.8% (N = 113) of cases, and 58.5% (N = 86) of cases were positive for having alcohol in their urine.

Anti-depressants such as Citalopram (N = 51 / 34.7%), hypnotic sedatives such as diazepam (N = 40 / 27.2%), non-opioid analgesics such as paracetamol (N = 28 /19%), and opioid analgesics such as co-codomol (N = 24 / 16.3) (see Table 5) were the most commonly reported substances alongside cocaine and alcohol.

Table 5.

Proportions of substance category other than cocaine and alcohol in descending order.

	(N / %)
Anti-depressant	51 / 34.7
Hypnotic/sedatives	40 / 27.2
Non-opioid analgesics	28 /19.0
Opioid analgesics	24 / 16.3
Heroin/morphine	20 / 13.6
Antihistamines	17 / 11.6
Anti-psychotic	15 / 10.2
Cannabis	14 / 9.5
Anti-epileptic	13/ 8.8
Acaricide	9 / 6.1
Anti-protozoal	8 / 5.4
Methadone	8 / 5.4
Anti-Rheumatological	8 / 5.4
Entactogenic compounds	7 / 4.8
Ulcer healing medication	6 / 4.1
General anaesthetic	6 / 4.1
Amphetamines	6/ 4.1
Other*	37 / 25

Note: *other = substances found in five decedents or less, included anti-arrythmia, anti-diarrhoeal, naloxone, anti-emetic, anti-infection, beta-blockers, bronchodilators, anti-diabetic agents, gases, GHB, local anaesthetic, Parkinsons medications, and phenothiazines.

Mental and physical health case complexity proxies

Sixty cases (40.8%) were in receipt of prescription medications. Forty-eight cases (32.6%) had medications prescribed for mental health conditions, and a further 25 cases (17%) had medications documented for physical health conditions. Each case was assigned a complexity rating for their physical and mental health based on the number of prescriptions and the type of medications prescribed.

Of the 48 cases who reported having a prescription to address mental health issues, 21 (43.75%; Table 6) were considered low complexity and in receipt of sertraline for depression (N = 7), risperidone for psychosis (N = 2) or zopiclone for sleep disorders (N = 4). Twelve cases (25%) were considered medium complexity, including those who had multiple prescriptions for first-line medications or had prescriptions for second- or third-line medications such as mirtazapine for depression (N = 13), chlorpromazine for psychosis (N = 1), or diazepam for insomnia or anxiety/panic disorders (N = 6). Finally, 15 cases were considered highly complex (31.2%) in view of receiving multiple (three or more) prescribed medications, or medications indicative of treatment-resistant conditions. These cases also tended to have medications spanning multiple therapeutic targets. For example, combined prescriptions of first- and second-line anti-depressants (venlafaxine PLUS mirtazapine) and combined prescriptions of first- and second-generation antipsychotics (haloperidol plus olanzapine).

Table 6.

Case complexity based on prescribed medicine.

Anti-depressants	(N / %)
No prescription	104 / 70.7
1	27 / 18.4
2	13 / 8.8
3+	3 / 2.0
Anti-psychotics
No prescription	137 / 93.2
1	7 / 4.8
2	2 / 1.4
3+	1 / 0.7
Hypnotic / sedatives
No prescription	137 / 90.5
1	4 / 2.7
2	5 / 3.4
3+	1 / 0.7
Mental health case complexity rating
No prescription	99 / 66.7
1 (low)	21 / 14.3
2 (moderate)	12 / 8.2
3+ (high)	15 / 10.2
Opioid analgesics
No prescription	136 / 92.5
1	1 / 0.7
2	8 / 5.4
3+	2 / 1.4
Anti-epileptics
No prescription	141 / 95.9
1	6 / 4.1
Physical health case complexity rating
No prescription	122 / 83.0
1 (low)	8 / 5.4
2 (moderate)	7 / 4.8
3+ (high)	10 / 6.8

The same approach was taken to summarise the complexity of medications for physical health conditions. However, only 15 cases were prescribed medications that were not focused on addressing mental health conditions. Of those, eight cases (32%; Table 6) were rated as low complexity with medications such as first-line antihistamines, and anti-epileptics being prescribed. Seven cases (28%) were rated as moderately complex with medications including opioid analgesics like tramadol and codeine being prescribed, as well as opioid substitution therapies including methadone. Finally, 10 cases (40%) were rated as being highly complex due to the number and type of medication listed. These cases included medication like fentanyl and morphine being prescribed (N = 2) or multiple medications across different drug categories (e.g. opioid agonists and anti-epileptic agents).

Discussion

Summary findings and sociodemographic profile

Using data collated between 2007 to 2023 by the NPSUM we demonstrate that individuals whose coroner report documents suicide, and the presence of cocaine and alcohol (or cocaethylene) represent a group of disproportionate complexity and vulnerability. Indeed, cocaethylene may serve as a biochemical marker of high-risk substance use behaviour related to psychiatric comorbidities and an increased risk of suicidality. These findings are broadly consistent with earlier analyses conducted on NPSUM data which have similarly reported that suicide decedents with evidence of substance use are predominantly male, relatively young, and often exhibit complex patterns of polydrug use (Ghodse et al., 2010; Schifano et al., 2012). More recent NPSUM-based work has also examined suicide determinations in relation to specific drug classes (Oyekan et al., 2021), further underscoring the value of toxicological profiling in understanding substance-related suicides. However, the present cohort shows a comparatively higher prevalence of alcoholcocaine co-use, highlighting stimulant use as a distinct risk profile within substance-related deaths. While these deaths are not always due to direct overdose, substance use can still contribute indirectly by affecting mood, impulse control, or behaviour, thereby influencing the risk of suicide.

The majority of cases were males between the ages of 25 and 45, living in the highest deprivation areas with a history of mental health conditions, substance use, a chronic physical health condition or known previous suicide attempts. This reflects the national (Office for National Statistics, 2023) and international (Eurostat, 2026) evidence which suggest that suicide rates are disproportionately higher among young men who take part in polydrug use. In 2025, in excess of 680,000 16- to 59-year-olds were frequent (≥1/month for 12 months) drug users in England and Wales (Office for National Statistics, 2025a). Of those reporting drug use in the previous year, 2.1% of 16- to 59-year-olds report use of powdered cocaine (Office for National Statistics, 2025a). Both recreational and dependent level drinking habits in the UK have also risen based on previous years (House of Commons Library, 2024; Medical Council on Alcohol, 2024). Furthermore, based on prescribing patterns alone, over 50% of patients with mental health conditions prescribed medications were considered medium or high-risk. These characteristics in the present sample reflect those already established in the literature as being at an elevated risk of both substance use and suicidality (Athey et al., 2024). This is especially worrying given the well documented trend of men being less likely to engage in mental health services and tendency to select more lethal methods of suicide which often results in them completing suicide (Burke et al., 2022; Smith and Hebdon, 2024). This is illustrated in the present sample where hanging was the most common method employed.

Conversely, while the majority of the sample was reported as having a non-manual occupation, 60% fell within the lower four deprivation deciles based on national indices suggesting a significant socio-economic disadvantage. This discrepancy could represent a number of factors such as underemployment, job insecurity or low-income employment which are known to contribute to psychological stress, substance use and suicidality (Skinner et al., 2023). Drug and alcohol consumption, social deprivation and health inequalities have previously been linked with increased risk of self-harm and suicide, with suicide rates being more than double among those in the 30- to 40-year-old bracket living in the most deprived areas when compared with the least, and men in their 40s and 50s living in the most deprived areas facing the highest rates of suicide of any age or gender (Office for National Statistics, 2025b). Furthermore, the impact of both dependent and recreational drug and alcohol consumption (Jane-Llopis and Matytsina, 2006), and social deprivation (Department of Health and Social Care, 2017) on poor mental health, which is also an independent risk factor for suicide (Randall et al., 2014; Yeh et al., 2019), is well established.

There were no documented instances where a deceased individual was clearly marked as having no significant risk factors before their death. While some cases may have “unknown” histories, this lack of information does not mean there are no underlying issues present. In cases where adequate information was available, at least one risk factor (such as mental health problems, substance abuse, relationship issues, health problems or engagement with the criminal justice system) was identified.

Psychological and pharmacological complexity

The data reveal a substantial burden of psychiatric morbidity among the individuals who completed suicide following the ingestion of cocaine and alcohol. More than half the sample (51%) had a documented history of mental health difficulties and roughly one third (32.6%) were in receipt of psychoactive medication at the time of their deaths. The pharmacological profiles of these individuals illustrate not only the complexity of psychiatric treatment within this population but also the prevalence, a pattern observed elsewhere in the literature (Xie et al., 2025). A meaningful proportion (31.2%) of those in receipt of mental health medication were classified as highly complex based on polypharmacy or prescriptions indicative of treatment-resistant conditions. For example, medications like clozapine, used primarily in cases of refractory schizophrenia (National Institute for Health and Care Excellence, 2014; Raguraman et al., 2005), suggest a subset of individuals suffering severe and persistent mental illness. High complexity was also expressed in cases which involved combinations of anti-depressants (e.g. venlafaxine and mirtazapine) or in some cases, co-prescription of both first and second-generation antipsychotics, patterns which have been associated with greater symptom burden, poor treatment response or discontinuities in care (Shakir et al., 2024). The medium-complexity cases showed similar patterns of risk, and even cases rated as low complexity displayed indicators of potential complexity; for example, many involved monotherapy with SSRIs or sedatives. While these data do not allow for prediction, the fact that 40.8% of the total sample were in receipt of prescription medication of any kind indicates that it is reasonable to propose that most had contact with mental health services preceding their death but this did not translate into effective prevention. This highlights the challenges of addressing suicidality in an already complex population and that the risk of completing suicide is significant across the spectrum of patient complexity. However, the present data do not allow for greater nuance regarding the contextual factors such as treatment adherence or therapeutic efficacy, nor does it examine barriers to effective treatment or fragmented treatment. Future research should examine these factors, especially in light of the high rates of deprivation found within this population and the practical challenges that this raises for individuals seeking to access treatment provisions.

Means and methods of suicide

The predominance of hanging (72.1%) as the method of suicide in the sample is consistent with trends reported elsewhere (Shah and Buckley, 2011) where it has emerged as one of the most common and lethal means, particularly among males (Eurostat, 2026; Office for National Statistics, 2025b). The prevalence of this method could be due to its perceived immediacy and accessibility, factors which can facilitate impulsive actions in moments of acute distress (Biddle et al., 2010). This is especially salient in the context of co-ingestion of alcohol and cocaine where the likelihood of disinhibition or impulsive decision making is increased (García-Marchena et al., 2018). These factors further increase the risk that suicidal ideation can escalate rapidly into lethal action.

Hanging was followed by mixed substance intoxication (15.5%) and single substance intoxication (4.1%) as the next most common means. While it is difficult to say for certain, it is not unreasonable to hypothesis that this could reflect the ambivalence or intent behind the act, which raises important questions regarding the role of impulsivity, diminished self-control and emotional dysregulation. This is further complicated by the mixture of psychoactive substances (prescribed and illegal) which further complicate the interpretation of intent. For example, substance use could represent a chronic coping mechanism that resulted in unintentional overdose, or it may have been a deliberate strategy to facilitate self-harm. Conversely, methods which required more substantial planning or involved multiple injury were less common, potentially underlining the role of impulsivity as a risk factor to suicide in this population, though this is speculative. What is clear, however, is that there is meaningful diversity in methods and that a comprehensive risk assessment should not only address a person's psychiatric profile, but also their substance use profile and prior behaviour patterns, a sentiment outlined elsewhere in the literature (Pirkis et al., 2024).

Public health and clinical implications

The present cohort illustrates the well documented link between social inequality, substance use and suicide (Phillips, 2025). Given the complexity of the sample, interventions aimed at reducing suicidality in substance using population must also take in to account the wider context of a person's life. This includes structural determinants such as housing status (Lee, 2022), employment (Kposowa et al., 2019), financial insecurity and social isolation (Motillon-Toudic et al., 2022) which are an important part of the overall picture when examining suicidality (Pirkis et al., 2024). This evidence also highlights the value of cross-sector collaboration as many who are at risk of suicide may present to a wide range of services such as health service, social care and housing as well as criminal justice, further underlining the need for the development of responsive pathways which can identify at-risk individuals (Kapur et al., 2025). While the present sample is limited in size, it does highlight the need to address poly-substance use not only as a substance use issue but also as a direct and indirect (or compounding) risk factor for suicide.

The presence of cocaethylene (though variably reported) can be regarded as a meaningful biomarker of elevated risk of suicidality. Cocaethylene is known to be more cardiotoxic and potent in a psychoactive sense than cocaine alone (Shastry et al., 2023) and its presence reflects a pattern of substance use which is more harmful than mono-drug use. While the actual pharmakinetic effect Cocaethylene has on suicide in a direct sense is not understood, it is reasonable to regard it as an indicator of greater risk of suicide if nothing else. From a clinical perspective, those presenting to services with both alcohol and stimulant use should be screened not only for substance dependence but also suicidal ideation and underlying psychiatric conditions.

Similarly, the meaningful overlap between psychiatric treatment complexity, substance use and suicide in the present cohort suggests a need for more integrated, multidisciplinary care model which encompasses multiple sectors (e.g. care, community, criminal justice). Specifically, those prescribed multiple psychotropic medication (possibly indicative of treatment resistance) may benefit from increased monitoring, case management and coordinated collaboration between psychiatric, primary care, criminal justice and substance use services as a joined up approach which takes a holistic view of a person and the context in which their symptoms occur. The calls for such an approach are outlined in existing government and international guidelines, including NICE recommendations on coexisting severe mental illness and substance misuse (NG58, National Institute for Health and Care Excellence, 2016) and on mental health in the criminal justice system (NG66, National Institute for Health and Care Excellence, 2017), U.S. guidance from SAMHSA on integrated and trauma-informed care (2015) and the World Health Organization's Integrated Operational Framework for Mental Health, Brain Health and Substance Use (2023). However, the practicality of doing this is challenging (Ryan and Oquendo, 2020) and resource intensive.

This study had several limitations that must be acknowledged. This study relies on coronial data which varies in scope and completeness, particularly in term of psychological and physical context of the decedent but also the toxicological reporting. The retrospective nature of the study also limits the ability to infer causality or examine contextual factors relating to the event (such as treatment adherence, service engagement or subject experience of distress). Additionally, the current dataset includes only cases from Wales, England and Northern Ireland; data from Scotland are not included. Nevertheless, this study provides useful commentary on the intersection of cocaine and alcohol, psychiatric morbidity, socioeconomic disadvantage and how they combination represents a meaningful constellation of suicide risk. Future research should examine how clinical and sociodemographic data (including mental and physical health information, treatment histories, prescribed medications, as well as housing, employment and relationship status) could be better captured and integrated to inform epidemiological efforts aimed at identifying risks for suicidality before death occurs. One approach that could provide richer insights is the use of psychological autopsies, which systematically reconstruct the psychosocial and psychiatric circumstances preceding death through interviews, records and coroner reports (Amritha et al., 2025; Johal et al., 2024). Indeed, psychological autopsy methods have been employed locally by NPSAD to deepen understanding of suicide cases, and integrating such approaches with broader epidemiological datasets could strengthen prevention strategies. Furthermore, efforts should be made to include Scottish data from the National Drug-Related Deaths Database (ScotSID) to enable conclusions that are applicable across the entire UK, and to examine other substances combinations (e.g. opioids and benzodiazepines) that have been linked to elevated suicidality.

Conclusion

In conclusion, this study provides a nuanced exploration of suicide deaths involving the co-ingestion of cocaine and alcohol. It highlights a subgroup marked by significant psychiatric, pharmacological and social complexity. This evidence suggests that cocaethylene may serve not only as a biochemical marker for high-risk substance use but possibly as a proxy for acute psychiatric vulnerability. The demographic profile of the sample reflects not only broader trends in the suicide literature, but that the presence of complex polypharmacy, severe mental illness and high-lethality methods further underscore the clinical and public health significance of this group. These findings highlight the importance of clinicians advising at-risk individuals about the heightened dangers of recreational alcohol and cocaine use, both in terms of health harms and suicide vulnerability.

Footnotes

ORCID iDs

Nyle Hawk Davies

Darren Quelch

Bev John

Philip Tyson

Caroline Copeland

Sally Bradberry

Mark Pucci

Gareth Roderique-Davies

Ethical considerations

This study received ethical approval as a secondary data analysis from the University of South Wales Faculty of Life Sciences and Education Ethics Panel.

Consent to participate

Not applicable.

Consent for publication

Not applicable.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

Declaration of conflicting interests

The authors declared no potential conflicts of interest with respect to the research, authorship and/or publication of this article.

Data availability

The data from this study are available on request from Caroline Copeland (caroline.copeland@kcl.ac.uk). The data are not publicly available due to privacy or ethical restrictions.

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